It’s VERY different!
If you are trying to decide between PhD in the US vs PhD in the UK, you should think more about fit. There are following 11 major differences in the two systems and choose the one that fits you the best:
#1 Masters Degree
Typically, in Europe, you would join a PhD program after completing your Master’s degree. In the US, you would spend a few years taking courses (alongside research) to get you a Master’s degree.
If you already have a Master’s degree, you may get course waiver, which could reduce your duration of PhD completion.
#2 Choose your project before starting your PhD
In the UK (and Europe), you typically choose a project before starting your PhD. This is different from the US, where you typically apply to a department for your PhD first and your thesis and research typically evolves in a year or two.
Some students may prefer the US model as that helps in ensuring greater fit between them and the lab and the advisor they got admit with.
#3 No classes
There are no class requirements for a PhD in the UK. You begin doing research right away. The assumption is PhD students know their research areas. After all, you start by applying to a professor / lecturer with a research area in mind.
Now, that might be true for some students. Others may want to get exposed to new ideas and potential research topics. In addition, they may also want to have wider peer group that gets formed in classes.
#4 Time to completion
Phd In the UK (and rest of Europe) are of 3 to 4 years duration. In the US, a PhD may take up to 5 to 6 years.
After a PhD in the UK, students are expected to go for postdoc. After a PhD in the US, more students go directly from graduation to academia or research jobs without a postdoc.
In many UK (and European) universities, there are firm guidelines on just how long a PhD takes and those are more important than individual decisions by a student’s advisors. In comparison, in the US, some students simply fly through their PhD in 3 years as they did some amazing research whereas other students slowly slog through 8 to 10 years of PhD as they were slow in producing research output.
There are different systems within Europe.
In Sweden and other Scandinavian countries, a PhD takes 4 to 5 years and include additional teaching duties. Students in these schools are considered as employees. They receive monthly salaries which are comparable to graduate students earning from industry and are taxable. A PhD students is allowed to either present or attend at least one conference anywhere in the world, expenses for which are taken care of by the research group.
In Germany, a 4 years PhD is considered too long and funding might not be available after first three years of the PhD program.
#5 Work life balance
PhD lifestyle is much more relaxed in the UK (and in Europe). You will have more time for yourself as well as your friends and family in the UK, while pursuing your PhD.
In the US, PhD students are often overworked with more teaching and grading responsibilities. They also have a lot of class work.
However, this is less about PhD and more about the cut rural difference between the UK (and Europe) and the US. The real questions here is, what culture you want to live in.
#6 Hierarchical structure
Some of the PhD programs in the UK will have Professor as the overall head of the project (or lab) with Reader under him, who in turn will have Lecturer under him.
Some students feel this hierarchy limits their opportunities to get exposure to head of lab and results in less interaction with the lab.
#7 Future opportunities
Some students do feel that the US offer more opportunities for PhD students in academia as well as jobs. This is true for the US has many more universities offering teaching position as well as many more companies offering jobs to PhD students. However, you will have to hustle to find a great job after your PhD, whether you do your PhD from the US or the UK. Within academic, there are more qualified applicants than the jobs. In companies, few people have PhD and your challenge will be to explain them your skills and research area.
#8 Different stipend (salary)
For most PhDs in UK (and Europe), stipend (or salary) comes centrally from the universities or from Government research organizations. These stipends (or salaries) may be limited to only 3 years duration of PhD.
In the US, stipend (or salary) comes directly from your supervisor without any limitation of the duration of PhD. Unlike big US universities, there are fewer TA responsibilities for PhD in the UK universities.
In may cases, you don’t need to pay tax on your income as a graduate students in the UK (and Europe).
In Germany, international students have the PhD positions as DAAD fellowship, where Germany government funds your PhD directly for 3 years.
#9 Less publications
In the UK, you have less chances of getting many publications. Your time is more focused on your thesis document.
#10 Less chance of faculty position afterwards
You don’t expect to move into a faculty position at the end of your PhD. To remain in academia, you may opt for postdoc positions.
Typically, you don’t find many European PhD graduates getting academic job offer in the US, unless they have done postdoc at a top US institution, with strong support letters from that institution.
#11 More similarity than differences
The UK (and European) universities are being influenced by the US system. Many UK universities’ Computer Science schools have Doctoral Training Programs which are essentially 4 year PhD programs, with the first year focused on teaching. These programs offer more flexibility about what you end up doing and who you end up working with. Also, these programs often are sponsored by industries, which means these have higher stipends and you may get an advisor in industry.
So, which one to choose – UK (or Europe) PhD vs US PhD?
Apart from factors mentioned above, you should focus in the quality of the research group and reputation of the professor. You should look at the top conferences in your topic of interest and note where does most of the papers come from. That’s your best clue as to which university / school you should choose.